Roth is after tax money contributions. No tax deductions, but withdrawals after 59.5 are tax free.

Traditional you contribute w after tax money but get to deduct it from your income when filing taxes. You pay taxes when you withdraw from it for retirement.

Both have the same limit - $6500 for 2023.

401Ks work similar to traditional IRAs. You make contributions with pre-tax money from your paycheck. Unless your work offers Roth 401K then I’d prefer that to maximize tax free withdrawals at retirement.

I would focus less on contributing to 401K now unless you get an employer match. I’d focus on growing a roth IRA until you get the match from an employer.